This is the second year sales rose in the United States; last year, they jumped 11 percent, according to PGI.

The numbers come from a retail survey conducted by the Jewelry Industry Research Institute.

According to PGI, last year overall U.S. sales of jewelry rose 5 percent by units, but 1.5 percent by value, due to heavy discounting by retailers.

PGI noted that platinum jewelry sales have been helped by sales at lower price points, especially now that it no longer costs significantly more than gold. (During 2014, platinum’s average price was $1,386 an ounce. Gold was $1,266 an ounce.) It is also frequently used in diamond engagement rings, sales of which rebounded last year, PGI said.